Every "thing" has its own time, and time may be affected by many things such as gravity and speed. E.g: When you approach a black hole the time for an outside observer will be slowing down on you as you approach it, but to you it will be completly normal and as fast as it has ever been. Also, when you travel at the speed of light and go for,let us say, a tow minutes trip, when you come back you will find that all your friends are old and some dead. this means that time is different when the observer and it is not the same everywhere. this difference is unnoticable because the speeds we reach are very slow in relative to that of light. All these are thoughts of the relativity and are well known. Execuse me for my poor english.